FrontendCommon: Add a post processing implementation

src/frontend-common/postprocessing_shader.h

@@ -0,0 +1,106 @@
+#pragma once
+#include "common/rectangle.h"
+#include "core/types.h"
+#include <array>
+#include <string>
+#include <string_view>
+#include <vector>
+
+namespace FrontendCommon {
+
+class PostProcessingShader
+{
+public:
+  enum : u32
+  {
+    PUSH_CONSTANT_SIZE_THRESHOLD = 128
+  };
+
+  struct Option
+  {
+    enum : u32
+    {
+      MAX_VECTOR_COMPONENTS = 4
+    };
+
+    enum class Type
+    {
+      Invalid,
+      Bool,
+      Int,
+      Float
+    };
+
+    union Value
+    {
+      bool bool_value;
+      s32 int_value;
+      float float_value;
+    };
+    static_assert(sizeof(Value) == sizeof(u32));
+
+    using ValueVector = std::array<Value, MAX_VECTOR_COMPONENTS>;
+    static_assert(sizeof(ValueVector) == sizeof(u32) * MAX_VECTOR_COMPONENTS);
+
+    std::string name;
+    std::string ui_name;
+    std::string dependent_option;
+    Type type;
+    u32 vector_size;
+    ValueVector default_value;
+    ValueVector min_value;
+    ValueVector max_value;
+    ValueVector step_value;
+    ValueVector value;
+  };
+
+  PostProcessingShader();
+  PostProcessingShader(std::string name, std::string code);
+  PostProcessingShader(const PostProcessingShader& copy);
+  PostProcessingShader(PostProcessingShader& move);
+  ~PostProcessingShader();
+
+  PostProcessingShader& operator=(const PostProcessingShader& copy);
+  PostProcessingShader& operator=(PostProcessingShader& move);
+
+  ALWAYS_INLINE const std::string& GetName() const { return m_name; }
+  ALWAYS_INLINE const std::string& GetCode() const { return m_code; }
+  ALWAYS_INLINE const std::vector<Option>& GetOptions() const { return m_options; }
+
+  bool IsValid() const;
+
+  const Option* GetOptionByName(const std::string_view& name) const;
+  Option* GetOptionByName(const std::string_view& name);
+
+  std::string GetConfigString() const;
+  void SetConfigString(const std::string_view& str);
+
+  bool LoadFromFile(std::string name, const char* filename);
+
+  bool UsePushConstants() const;
+  u32 GetUniformsSize() const;
+  void FillUniformBuffer(void* buffer, u32 texture_width, s32 texture_height, s32 texture_view_x, s32 texture_view_y,
+                         s32 texture_view_width, s32 texture_view_height, u32 window_width, u32 window_height,
+                         float time) const;
+
+private:
+  struct CommonUniforms
+  {
+    float src_rect[4];
+    float src_size[2];
+    float resolution[2];
+    float rcp_resolution[2];
+    float window_resolution[2];
+    float rcp_window_resolution[2];
+    float time;
+    float padding[1];
+  };
+
+  void LoadOptions();
+
+  std::string m_name;
+  std::string m_code;
+  std::vector<Option> m_options;
+};
+
+} // namespace FrontendCommon